The idea of flying satellites in “very” low-Earth orbit is not new. Dating back to the dawn of the space age in the late 1950s, the first US spy satellites, as part of the Corona program, orbited the planet as low as 120 to 160 km (75 to 100 miles) above the Earth.
This low vantage point allowed the Kodak cameras on board the Corona satellites to capture the highest-resolution images of Earth during the height of the Cold War. However, flying so close to the planet brought a number of challenges, most notably that of atmospheric drag.
For much of the space age, therefore, satellites have flown much higher orbits. Most satellites today fly at an altitude of between 400 and 800 km (250 and 500 miles), which is high enough to avoid the vast majority of atmospheric drag while still being close enough to offer good communications and a clear view of the planet.
In recent years, a handful of new space companies have announced plans to develop small- and medium-size satellites designed to survive in very low-Earth orbit (VLEO) and capable of taking advantage of the closer-in vantage point. The first of these companies to actually reach the launch pad is a Denver-based startup named Albedo.
Hello, startup
Albedo was founded about four years ago by two engineers from Lockheed Martin, Topher Haddad and Ayjay Lasater, and a software engineer from Facebook, Winston Tri. Since 2021, the trio has raised more than $100 million to develop satellites capable of delivering visual images with a resolution of 10 cm.
“The vision was to commercialize VLEO as a means to capture imagery at a resolution that today you can only get from planes or drones or commercially, or from billion dollar national systems on the national security side,” Haddad said in an interview.
This resolution is significantly higher than any currently available commercial satellite imagery and rivals the resolution of some of the best spy satellites currently operated by the US and other large space powers.
For high-resolution imagery today, Haddad said, sometimes the only real solution is helicopters or drones. But there are many locations on the planet that restrict fly overs, and the cost for regular over-flights by aircraft adds up quickly.
Clarity-1 at the pad
Albedo’s first big test may come within the next week and the launch of the “Transporter-13” mission on SpaceX’s Falcon 9 rocket. The company’s first satellite, Clarity-1, is 530 kg (1170 pounds) and riding atop the stack of ridesharing spacecraft. The mission could launch as soon as this coming weekend from Vandenberg Space Force Base in California.
The Clarity-1 satellite will be dropped off between 500 and 600 km orbit and then attempt to lower itself to an operational orbit 274 km (170 miles) above the planet.
This is a full-up version of Albedo’s satellite design. The spacecraft is larger than a full-size refrigerator, similar to a phone booth, and is intended to operate for a lifetime of about five years, depending on the Solar cycle. Clarity-1 is launching near the peak of the 100-year cycle, so this could reduce its active lifetime.
Albedo recently won a contract from the US Air Force Research Laboratory that is worth up to $12 million to share VLEO-specific, on-orbit data and provide analysis to support the development of new missions and payloads beyond its own optical sensors.
Serving many different customers
The advantages of such a platform include superior image quality, less congested orbits, and natural debris removal as inoperable satellites are pulled down into Earth’s atmosphere and burnt up.
But what about the drawbacks? In orbits closer to Earth the primary issue is atomic oxygen, which is highly reactive and energetic. There are also plasma eddies and other phenomena that interfere with the operation of satellites and degrade their materials. This makes VLEO far more hazardous than higher altitudes. It’s also more difficult to capture precise imagery.
“The hardest part is pointing and attitude control,” Haddad said, “because that’s already hard in LEO, when you have a big telescope and you’re trying to get a high resolution. Then you put it in VLEO, where the Earth’s rotation beneath is moving faster, and it just exacerbates the problem.”
In the next several years, Albedo is likely to reach a constellation sized at about 24 satellites, but that number will depend on customer demand, Haddad said. Albedo has previously announced about half a dozen of its commercial customers who will task Clarity-1 for various purposes, such as power and pipeline monitoring or solar farm maintenance.
But first, it has to demonstrate its technology.